More MixIns in XML tests.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@12393 e27351fd-9f3e-4f54-a53b-843176b1656c
AttributeError, not AssertionError, when setting a read-only attribute.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@12394 e27351fd-9f3e-4f54-a53b-843176b1656c
Bring in DirectoryServiceRealmTestMixIn


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@12395 e27351fd-9f3e-4f54-a53b-843176b1656c
Pull in DirectoryServiceQueryTestMixIn and mark tests as todo for now.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@12396 e27351fd-9f3e-4f54-a53b-843176b1656c